Applications menu doesn't scale XPM pixmaps

When the Applications menu displays a menu item where the icon is a .xpm pixmap, it doesn't scale the icon, causing different forms of graphical overflow.

Scenario:
- start Settings Manager
- open Main Menu editor
- add a new menu item to some sub-menu
- set icon on menu item to Image Files and /usr/share/pixmaps/xterm-color_48x48.xpm

Expected result:
- menu item should have a scaled icon

Actual result:
- menu item shows the center of clipped icon
- when hovering the menu item icon overflows text

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: xfce4-panel 4.10.0-1ubuntu2
ProcVersionSignature: Ubuntu 3.5.0-18.29-generic 3.5.7
Uname: Linux 3.5.0-18-generic x86_64
ApportVersion: 2.6.1-0ubuntu6
Architecture: amd64
Date: Mon Nov 26 14:24:14 2012
ExecutablePath: /usr/bin/xfce4-panel
InstallationDate: Installed on 2012-11-05 (20 days ago)
InstallationMedia: Xubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.1)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: xfce4-panel
UpgradeStatus: No upgrade log present (probably fresh install)
XsessionErrors:
 (xfsettingsd:2062): xfsettingsd-WARNING **: Unknown mode '1920x1200 @ 60.0' for output VGA1.
 (polkit-gnome-authentication-agent-1:2079): GLib-CRITICAL **: g_variant_new_string: assertion `string != NULL' failed
 (polkit-gnome-authentication-agent-1:2079): polkit-gnome-1-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files
 (xfce4-indicator-plugin:2178): libindicator-WARNING **: IndicatorObject class does not have an accessible description.
 (xfce4-indicator-plugin:2178): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed